Benzene, toluene, ethylbenzene, and xylene are all solvents that are commonly referred to as BTEX solvents. An aromatic hydrocarbon solvent, such as a BTEX solvent, allows for azeotropic distillation prior to the formation of a final product, such as a non-emulsifying agent in a non-limiting example. An azeotrope is a mixture of two or more liquids where the total composition of the mixture cannot be changed by simple distillation, i.e. boiling the liquid mixture produces a vapor having the same ratio of liquid components as that of the liquid mixture. Therefore, azeotropic distillation is a technique applied to change the ratio of components within an azeotrope. One specific technique may include adding another component or solvent to the liquid mixture, so that a new azeotrope with a lower boiling point is produced. A common example of this is done by adding benzene, a BTEX solvent, to water and ethanol to dehydrate the ethanol/water mixture. When the BTEX solvent is added to the mixture, the molecular interactions change and a new lower boiling azeotrope is formed. In actual practice the BTEX solvent produces water and an immiscible organic phase.
BTEX solvents have attracted much attention in recent years because these solvents tend to contaminate groundwater reservoirs, which poses serious health concerns for the public. BTEX solvents are considered strong carcinogens and are highly mobile in the soil and groundwater environment. This well-founded concern lies in the constant use of these solvents in areas including fuel operations, refineries, gasoline stations, and gasification sites. Thus, the use of BTEX solvents has declined.
BTEX solvents are toxic to humans, and diminishing the use of these solvents is of special interest. It would be desirable if a method were devised for preparing non-emulsifying agents, oil soluble imidazoline corrosion inhibitors, oil soluble alkylphenolic resins, paraffin inhibitors, defoamers, oil soluble scavengers, oil soluble cleaners, hydrotropic wetting agents, oil soluble surfactants, foamers and the like in a manner that is less harmful to the environment.